4-3 · Music Theory: Triads

Triads are essential building blocks for music, and they are a powerful tool for finding target notes while chord tone soloing. For our purposes, a triad is a three-note chord created by stacking two sequential intervals, either of which can be a major or minor third.

There are four triads that can be created this way:

When created by stacking thirds, the lowest note of a triad is called the root. The next note is called the third, and it is either a major or minor third above the root. The last note is called the fifth. In a major or minor triad, the interval between root and fifth is a Perfect 5th.

If the root is the lowest note played, the fifth is the highest, and the third is in the middle, that arrangement is called a root position triad.

If the root is raised up an octave, so the third is now on the bottom, that arrangement is called first inversion.

If we then move the third up an octave, so that the fifth is now the lowest note, the triad is then in second inversion.

On each set of three strings, there are exactly three ways to play closed-form triads (meaning the notes are all inside one octave), one corresponding to each inversion.

Here are the A major triad inversions on the G, B, and e strings. Starting from the nut, these are root position, first inversion, and second inversion:

We can find similar fingerings for each of the other groups of three strings. Note that if not for the warp, each inversion type would always have the same fingering.

To create a minor triad from a major triad, we can simply move the third down one fret, changing it from a major third to a minor third. Here are the resulting A minor triad fingerings on each set of three strings:

You can create an augmented triad by raising the 5th of a major triad by one fret, and you can create a diminished triad by lowering the 5th of a minor triad by one fret.

It is not necessary to memorize these shapes for the purposes of this course, but they are absolutely worth learning and practicing, and I do recommend memorizing them as a part of your guitar journey. They are valuable as compact voicings for playing rhythm guitar, and they can play a large role in finding chord tone targets.

To get the most out of these shapes, learn where the root is in each fingering pattern. The fifth will always be one string lower or two strings higher. The third will always be one string higher or two strings lower.

Exercise 1: Choose a root and a set of three adjacent strings. Play the major triad in its three inversions. Repeat with additional string sets. Do the same with the minor triads.

Exercise 2: In a small area of the fretboard and on three adjacent strings, play the major triads for B, E, A, and D.

Exercise 3: Repeat exercise 2, but alternate between minor and major triads.

Create your own exercises by mixing and matching different variables: region of fretboard, set of strings, root notes, and major vs. minor. There are dozens of ways to practice this, and you should challenge yourself every time you practice.